Complex phosphate acid esters and their use in industrial metalworking processes are known in the art. For example, the Kipp et al U.S. Pat. Nos. 4,636,321 and 4,654,155 respectively disclose water soluble and water-emulsifiable metalworking lubricants which contain, among other ingredients, a complex organic phosphate ester. The organic phosphate esters are disclosed as being extreme pressure additives in the lubricant compositions. Similarly, the Kirk et al U.S. Pat. No. 4,758,359 discloses metalworking lubricants consisting essentially of water and complex organic phosphate esters. The phosphate ester additives are disclosed as providing lubricating functions and protecting metal surfaces from damage by tools and the like Additional lubricant compositions for working metals and containing phosphate compounds are also known in the art. For example, the Davis U.S. Pat. No. 3,310,489 discloses lubricant compositions for use in metalworking operations, which compositions contain a corrosion inhibitor which is the reaction product of an amine and a phosphate ester. The Shimada et al U.S. Pat. No. 3,496,104 discloses a cold rolling lubricant composition for steel plates, which composition comprises at least one water soluble organic phosphate ester compound as the lubricating agent. Similarly, the Gower U.S. Pat. No. 3,645,897 discloses water based lubricant compositions which may include extreme pressure agents comprising amine salts of fatty acids and organic phosphate esters.
Additional lubricant compositions comprising phosphate esters and/or derivatives thereof are disclosed in the Dubourg U.S. Pat. No. 3,788,988, the Smith et al U.S. Pat. No. 3,966,619, the Hellsten et al U.S. Pat. No. 4,384,965, the Anderson et al U.S. Pat. No. 4,521,321, the British Patent No. 1,043,488 and the Soviet Reference No. 1,011,677. These various references disclose the inclusion of phosphate esters and/or derivatives thereof for use as emulsifiers, dispersants, solubilizers, extreme pressure additives and the like in metalworking lubricant compositions.
The Ahlgrim et al U.S. Pat. No. 4,268,404 and the Schuster U.S. Pat. No. 4,303,540 disclose compositions useful as lubricants and/or coolants in the metalworking industry. More specifically, Ahlgrim et al disclose compositions comprising a long chain ammonium polyphosphate as an effective additive in lubricants and coolants for metalworking while Schuster discloses a cooling and lubricating agent produced by the condensation reaction between an excess amino alcohol with boric acid and the addition of a carboxylic acid to the complex boron containing diamine formed in the reaction system.
The Yu et al U.S. Pat. No. 4,593,745 teaches the use of various agents such as ethylene glycol, halogenated hydrocarbons, and simple organic phosphate triesters alone and in combination with water as fire and explosion resistant quenching media in the casting of metals. It is apparent that the fire resistant phosphate triesters of Yu et al differ in chemical structure from the complex organic phosphate acid esters employed in the present invention.
In many metalworking processes, thermal quenching of metal surfaces is required. Fast and uniform thermal quenching of metal parts is desired in providing improved processing and/or products. Accordingly, a continuing need exists for providing improved thermal quenching processes wherein the quenching time is reduced and/or the resulting thermal quenching is provided in a more uniform manner.